|
Search: id:A075840
|
|
|
| A075840 |
|
Primes of the form (2*n)!/(n!)^2+1. |
|
+0
2
|
|
| 2, 3, 7, 71, 3433, 2704157, 35345263801, 2104098963721, 6892620648693261354601, 410795449442059149332177041, 1520803477811874490019821888415218657, 5949105755928259715106809205795376486501
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
REFERENCES
|
New Zealand Science Monthly, Bulletin Board, Feb. 1999. Binomial(300,150)+185 = nextprime.
|
|
EXAMPLE
|
7 is a term because C(4,2)+1 = 6+1 = 7 is prime.
|
|
MATHEMATICA
|
a = Select[ Range[100], PrimeQ[Binomial[2#, # ] + 1] & ]; Binomial[2a, a] + 1
|
|
PROGRAM
|
(PARI) v=[]; for(n=0, 100, x=bin(2*n, n)+1; if(isprime(x), v=concat(v, x), )); v
|
|
CROSSREFS
|
Cf. A092751 = n such that (2*n)!/(n!)^2+1 is prime, A112858 = primes of the form (2*n)!/(n!)^2-1.
Cf. A000984, n's are in A066699.
Sequence in context: A130309 A090870 A088542 this_sequence A096225 A035094 A084729
Adjacent sequences: A075837 A075838 A075839 this_sequence A075841 A075842 A075843
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Donald S. McDonald (don.mcdonald(AT)paradise.net.nz), Oct 14 2002
|
|
EXTENSIONS
|
Edited by Robert G. Wilson v (rgwv(AT)rgwv.com), Oct 15 2002
Definition corrected by Alexander Adamchuk, Nov 30 2007
Edited by njas, Nov 30 2007
|
|
|
Search completed in 0.002 seconds
|
